The present invention relates to reusable closures suitable for sealing bags or other openings, for holding sheets of pliable material together, and for other such purposes. The invention further relates to methods of manufacturing such closures, and to packaging systems using such closures.
It is a common problem in many areas to find a way of closing and resealing bags once they have been opened, particularly paper or plastic bags. For example, food is often stored in plastic bags and these bags must be resealed after opening to prevent spoilage of any unused food. Zip-lock closures are often used to seal bags of food, but these are generally not of long lasting and durable construction so they do not withstand repeated use. Other locking closures are used, but they typically are also not of durable construction.
In the electronics industry, it is common to store a plurality of one type of electronic component in a bag of plastics or other material. It is a problem in this field to find a way of resealing such component bags which gives an air-tight, moisture-free, and anti-static seal. When one component is removed, the bags are commonly resealed with tape or staples. Tape will typically peel off under hot or moist conditions, and, when removed to re-open the bag, will often tear the bag material. Staples are no longer permitted as bag closures in many areas, and do not seal the bags properly so the components may deteriorate due to exposure to the atmosphere. In this area, the known anti-static zip lock bags do not have a long enough life over repeated locking action. Moreover, shrouding and covering of large items and equipment with a pliable material, such as shrouding of missiles and aerospace engines and the like, for storage and transport, can be a problem when attempting to tape or otherwise seal the covering material edges together.
In fields where a large number of different electronics or other parts have to be kept in storage so that they are readily accessible when needed, such as the military, aviation, aerospace, electronic, and construction industries, there are also problems in labelling bags. At present, peel-off labels are used to identify the products. These labels often peel off under hot or moist conditions, causing problems in identifying parts. Relabelling a bag is also difficult, since pulling off a label will often tear the bag material.